Electrospun Nylon-11 nanofibers for triboelectric energy harvesting

Triboelectric nanogenerators (TENGs) can be considered as effective means for mechanical energy harvesting applications for powering small scale electronic devices, triboelectric sensors etc. Here triboelectric charges are developed when two dissimilar surfaces are brought into contact and triboelectric nanogenerators harness this contact electrification to convert periodic mechanical vibrations or motion into electricity. In this work, the triboelectric properties of Nylon-11 electrospun polymer membranes were studied along its synthesis and material characterization. Nylon-11 is a tribopositive polymer which is also piezoelectric, having semi-crystalline nature and high thermal stability. From the SEM analysis, it was found that highly uniform and defect-free Nylon-11 nanofibers were obtained along with an increase in fiber diameter (from 150 to 400 nm) and membrane thickness (from 30 to 90µm as the electrospinning time varied from 3 to 9 hours. Moreover, piezoelectric crystalline phase formation was observed for the prepared electrospun fibers, which was confirmed using XRD technique. The triboelectric properties of the electrospun membranes (of varying thickness) were measured and maximum voltage (57 V) and current (5.8 µA) outputs were obtained for an applied force of 10 N at a frequency of 10Hz. Furthermore, very high outputs (up to 70 µA and 250 V) were generated by simple palm tapping on the fabricated Nylon-11 TENGs which underlines its effectiveness as an energy harvesting device.